Full Disclosure mailing list archives
Fun with event logs (semi-offtopic)
From: 3APA3A <3APA3A () SECURITY NNOV RU>
Date: Thu, 21 Dec 2006 15:22:09 +0300
Dear full-disclosure () lists grok org uk, There is interesting thing with event logging on Windows. The only security aspect of it is event log record tampering and performance degradation, but it may become sensitive is some 3rd party software is used for automated event log analysis. The problem is a kind of "Format string" vulnerability where user-supplied input is used for event log record. For ReportEvent() function %1, %2, etc have a special meaning and are replaced with corresponding string from lpStrings. The problem is this can be done recursively. That is, %2 argument can include itself. This fact doesn't lead to any buffer overflow, but you can fill entire buffer with relatively small argument. Most services do not escape any user-supplied input then constructing log event. You can see very interesting event log entries if you try something like: net send SOMEHOST %2 or net use \\SOMEHOST\IPC$ /user:%1%2%3 -- http://www.security.nnov.ru /\_/\ { , . } |\ +--oQQo->{ ^ }<-----+ \ | ZARAZA U 3APA3A } You know my name - look up my number (The Beatles) +-------------o66o--+ / |/ _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
Current thread:
- Fun with event logs (semi-offtopic) 3APA3A (Dec 21)
- Re: Fun with event logs (semi-offtopic) endrazine (Dec 21)
- Re: Fun with event logs (semi-offtopic) Tim (Dec 21)
- Re: Fun with event logs (semi-offtopic) 3APA3A (Dec 21)
- Re: Fun with event logs (semi-offtopic) Tim (Dec 21)
- <Possible follow-ups>
- Re: Fun with event logs (semi-offtopic) Michele Cicciotti (Dec 21)
- Re: Fun with event logs (semi-offtopic) Michele Cicciotti (Dec 21)
- Re: Fun with event logs (semi-offtopic) 3APA3A (Dec 21)
- Message not available
- Re: Fun with event logs (semi-offtopic) Michele Cicciotti (Dec 21)
- Re: Fun with event logs (semi-offtopic) endrazine (Dec 21)